Can not open project files

Hi. I run Audacity 2.0 on Windows 7 in norwegian. I am not much used to computerspeak, I hope I can make myself clear here.

When opening a saved project, by clicking on the .aup-file, I inadvertedly managed to change the standard program for opening the .aup-files, into iTunes. When trying to change it back, it will not accept Audacity as standard program for opening the .aup-files. It is not in the standard list, so I find it on my computer, click it, but the the box returns to the folder without changing neither the logo on the file or the program.

Maybe Audacity is not the program that opens the .aup-file?

Hope you understand my problem, thanks.

This problem can happen if you previously had a different version of Audacity installed.

See here: